No significant clinical differences between native or reduced posterior tibial slope in kinematically aligned total knee replacement with posterior cruciate-retaining

Giorgio Cacciola; Fortunato Giustra; Francesco Bosco; Daniele Vezza; Francesco Pirato; Lorenzo Braconi; Salvatore Risitano; Marcello Capella; Alessandro Massè; Luigi Sabatini

doi:10.1016/j.jor.2024.03.023

No significant clinical differences between native or reduced posterior tibial slope in kinematically aligned total knee replacement with posterior cruciate-retaining

J Orthop. 2024 Mar 14:54:32-37. doi: 10.1016/j.jor.2024.03.023. eCollection 2024 Aug.

Authors

Affiliations

¹ Department of Orthopaedics and Traumatology, University of Turin, CTO, Torino, Italy.
² Department of Orthopaedics and Traumatology, San Giovanni Bosco Hospital-ASL Città di Torino, 10154, Turin, Italy.
³ Department of Precision Medicine in Medical, Surgical and Critical Care (Me.Pre.C.C.), University of Palermo, Palermo, Italy.
⁴ Department of Orthopaedics and Traumatology, G.F. Ingrassia Hospital Unit, ASP 6, Palermo, Italy.
⁵ Humanitas Gradenigo, Department of Robotic and Minimally-Invasive Arthroplasty Surgery, 10153, Turin, Italy.

PMID: 38524363
PMCID: PMC10957378 (available on 2025-08-01)
DOI: 10.1016/j.jor.2024.03.023

Abstract

Aims & objectives: Total knee arthroplasty (TKA) is a common surgical procedure for end-stage knee osteoarthritis. However, conventional alignment techniques may lead to postoperative dissatisfaction in up to 20% of cases. Kinematic alignment (KA) has emerged as a new philosophy to restore the native joint line and achieve more natural kinematics. Preserving the posterior tibial slope (PTS) and posterior cruciate ligament (PCL) is crucial to maintaining the pre-arthritic joint line and improving knee kinematics. This study aimed to assess the prevalence of postoperative PTS changes and their impact on functional outcomes and range of motion.

Materials & methods: A retrospective single-center study was conducted on patients who underwent KA-TKA with PCL preservation. The preoperative and postoperative PTS were measured on lateral knee radiographs using the tibial proximal anatomic axis method. Patient-reported outcome measures (PROMs) were collected pre- and postoperatively up to a two-year follow-up.

Results: Of the 95 included patients, 62.1% achieved an anatomically similar PTS (within 3° from the preoperative value), while 37.9% experienced noticeable PTS changes. However, no significant associations existed between PTS changes and compromised PROMs (WOMAC, 22.2 and 23.1; FJS, 66.6 and 67.3), ROM (118.5° and 119.4°), or patient satisfaction. No postoperative complications requiring reoperation or component revisions were observed.

Conclusion: Preserving or modifying the native PTS during KA-TKA could be confidently undertaken without compromising functional outcomes or patient satisfaction.

Keywords: Kinematic alignment (KA); Posterior cruciate ligament (PCL); Posterior tibial slope (PTS); Total knee arthroplasty (TKA); Total knee replacement (TKR).